Farm tractors and the like are conventionally provided with rearwardly projecting tow bars and many implements, such as a pull-type BUSH-HOG are pulled behind conventional draft vehicles. These implements are conventionally provided with forwardly projecting tow bar assemblies including upper and lower tow bar portions having vertically registered openings formed therethrough and these tow bar portions are releasably connectible to an associated rearwardly projecting tow bar disposed between the upper and lower tow bar portions by a conventional hitch pin passed through the openings in the upper and lower tow bar portions as well as the associated rearwardly projecting tow bar.
However, these conventional pins include headed upper ends and rest by gravity with their upper end heads supported from the upper surfaces of the associated upper tow bar portions. If the draft vehicle and implement being towed therebehind through the utilization of such a conventional headed pin is moved over uneven terrain causing relative roll and pitch movements between the draft vehicle and the towed implement, considerable axial forces may be applied to the pin in a manner tending to strip the head of the pin from the upper end thereof. Although conventional pins of the above-referred to type function adequately while moving over even ground, when the draft vehicle and implement being towed therebehind are subject to relative roll and pitch movement, even the strongest pins being manufactured are unable to withstand continued usage without the heads of the pins being stripped therefrom or the pins incurring excessive wear beneath the head thereof or to the undersides of the heads and the opposing hitch upper surfaces. It is well-known that conventional hitch pins have such a short operating life and they are frequently displayed in many equipment stores as convenience items, in that they are prominently displayed as a reminder to any prospective purchaser that hitch pins are available in that particular equipment store.
Accordingly, a need exists for an improved form of implement hitch pin.
Examples of hitch pins including some of the general structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 1,887,054, 2,482,907, 3,190,677, 3,794,357 and 4,087,112.